Question

$4 \: aratati \: ca \: a = (3 {\\ }^{21} + 3 {}^{20} + 3 {}^{19}) \div 39 \: este \: patrat \: perfect$
ajutor vă rog du coroana. ​

Answer 1

Răspuns:

$a=3^{19} (3^{2} +3^{1} +1):39\\\\a=3^{19} *13:39\\\\a=3^{19} :3\\\\a=3^{18} = > a=(3^{9}) ^{2} p.p$

Answer 2

$a = 3 {}^{19} \times (3 {}^{2} + 3 {}^{1}+ 1) \div 39 \\ a = 3 {}^{19} \times 13 \div 39 \\ a = 3 {}^{19} \div 3 \\ a = 3 {}^{18} \\ a = (3 {}^{9} ) {}^{2} - patrat \: perfect$